Does anyone else feel that the punishment should go further to discourage others?

Is it reasonable that he is still employed by a firm that one would expect wants to uphold high professional standards?

If I were female lawyer (or would-be lawyer) I'd think so so carefully about going to join a firm where one of their senior partners is, according to the tribunal acting like this...
'Mr Dhennin offered no explanation for why he volunteered at the beginning of the hearing that in fact he did know of the claimant's pregnancy.
'We are not satisfied that the claimant would have been made redundant at the same time had it not been for the fact she told the respondent of her pregnancy.
What's even more upsetting is this quote...

"She was pregnant, and she was concerned how she would manage financially. She was generally upset, and she missed the children."

I don't want anything that follows to be interpreted as in any way condoning this behaviour, and if people choose not to work for a firm in which someone like this is a partner then fine, but we are lucky enough to live under the rule of law, not mob rule, and certainly not rule by Daily Mail, and we have established tribunals and courts to hear ALL the evidence and decide on a suitable punishment, and I think we should leave it like that.

Try reading this great passage from A Man for All Seasons:

Alice More: Arrest him!More: Why, what has he done?Margaret More: He's bad!More: There is no law against that.Will Roper: There is! God's law!More: Then God can arrest him.Alice: While you talk, he's gone!More: And go he should, if he was the Devil himself, until he broke the law!Roper: So now you'd give the Devil benefit of law!More: Yes. What would you do? Cut a great road through the law to get after the Devil?Roper: I'd cut down every law in England to do that!More: Oh? And when the last law was down, and the Devil turned 'round on you, where would you hide, Roper, the laws all being flat? This country's planted thick with laws from coast to coast– man's laws, not God's– and if you cut them down—and you're just the man to do it—do you really think you could stand upright in the winds that would blow then? Yes, I'd give the Devil benefit of law for my own safety's sake.

Couldn't agree more Chorister. Well said. Trial by The Daily Mail is no fair trial although on this occassion they are quoting the findings of a tribunal.
To reiterate I so do not condone discriminatory behaviour towards pregnant women.

I’m not sure on the fine, I guess it’s calculated to be appropriate based on the nanny’s lost income.

But in terms of trial by DM / mob justice, I think one of the reasons we are transparent about our legal system and have a press that reports on it is essentially to allow society to judge if they want to interact with someone based on their legal record / crimes and misdemeanours. So publishing (name & shame) just lets people decide if this is someone whose ethics you would trust. So presumably a few clients as well as potential employees will opt not to work with this guy. Rightly so from the sound of it. Can’t be trusted to do what’s right.

He does seem a bit of an idiot for sacking an employee during pregnancy. I will assume she was directly employed, ie not through an agency.
He would not be responsible for any maternity or paternity pay, am I right? In which case he could have hired another nanny on a fixed term contract.
Perhaps he was worried about short notice leave due to complications, check-ups or pregnancy fatigue, in which case a conversation regarding the commencement of maternity leave could rightly be initiated.
regardless, he blew it and deserved the fine.